CVE-2026-107508: Unknown Ultimate Multisite

High severity, CVSS 8.6. EPSS: 0.5% chance of exploitation in the next 30 days.

The Ultimate Multisite WordPress plugin before 2.17.2 does not validate a user-supplied value used to select a file to include, allowing unauthenticated attackers to include and read arbitrary local files, including the WordPress configuration file.

Affected products

• Unknown Ultimate Multisite: before 2.17.2 (fixed in 2.17.2)

Published 2026-10-14. Last modified 2026-10-14.